Folding arm assembly for a load pusher



July 29,1969 D..M.FAu --.T 3,45 7

FO-LDI-NGYARM ASSEMBLY FOR A LOAD PUSHER Filed July 17, 1967 Donald M.Faus1- INVENTOR United States Patent US. Cl. 214-514 4 Claims ABSTRACT OF THE DISCLOSURE A load pusher attachment for a lift truck including a frame, a. movable pusher disposed in front of the frame, and a single, foldable arm assembly interconnecting the frame and each side of the pusher for moving the latter toward and away from the former. Each arm assembly includes a unitary, channel-shaped primary arm anchored adjacent its rear end to a torque shaft journaled on one side of the frame, and a unitary channel-shaped secondary arm nestable within and hinged to the primary arm with a forward end mounted for movement transversely on, and constituting the sole support for, one side of the pusher.

This invention relates to a load pusher attachment for a lift truck, and more particularly, to an improved foldable arm assembly for moving a pusher back and forth in such an attachment.

Load pusher attachments have been proposed that include a pusher of substantially rectangular outline, and a folding arm assembly for each corner of the pusher supporting the pusher on the attachment frame. The two arm assemblies that support the two corners on each side of the pusher are joined at their rear extremities to a common, vertically-disposed torque shaft which is rotated to extend the arm assemblies. Because of the twisting of the torque shaft which occurs when the same is rotated to extend the pair of assemblies on the shaft, and the independent points of connection of the two arm assemblies with the pusher, problems have resulted when the pusher is forced heavily against a load. This is because the two arm assemblies do not unfold in an exactly coordinated fashion of turning of the shaft, and this, together with the independent connection of the arm assemblies, results in skewing and canting of the pusher.

Further, stressing of the parts in the attachment results, which leads to maintenance problems. Also, the multiplicity of arm assembliees that such a construction requires has the additional disadvantage of severely limiting visibility, contributing to the practical difficulties of operating the attachment.

Therefore, a general object of the present invention is to provide, in a load pusher attachment, novel folding arm structure interconnecting the frame and one side of the pusher where multiple and all points of connection with the side of the pusher are established through a unit arm in the arm structure.

More particularly, an object of the invention is to provide such an attachment which consists of a single folding arm assembly operatively interconnecting each side of the frame and a side of the pusher, and each arm assembly comprises a unitary primary arm mounted on the frame through a torque shaft journaled on the frame, and a unitary secondary arm hinged adjacent its rear end to the primary arm and mounted adjacent its forward end for movement transversely on the frame. The secondary arms of the two arm assemblies are pivoted together for interdependent operation, and the other ends of such arms constitute the sole support for the opposite sides of the pusher.

A special feature of the invention is a construction for the mounting of the forward end of a secondary arm in an arm assembly on a side of a pusher, whereby the secondary arm provides the necessary support for the pusher at relatively widely spaced apart points on the pusher side.

A further object is to provide arm assemblies of the type indicated, which are relatively compact, yet well suited to resist twisting and skewing during folding up and unfolding thereof. Thus, the arms of an assembly are formed of channel members having vertically-disposed centrol webs and flanges normal to the webs, with the channel member forming the secondary arm of an assembly being nestable within the channel member forming the primary arm of the assembly. The webs and flanges of the channel members provide suitable rigidity, and compactness results from the ability of the arms to nest within each other.

Yet another object of the invention is to provide an organization wherein the folding arm assemblies which mount the pusher on the attachment frame are positioned adjacent the bases of the frame and pusher, with the assemblies closely spaced and occupying only a relatively small part of the space between the frame and pusher. Such a construction, from a truck operators point of view, affords good visibility of a load in front of the pusher.

These and other objects and advantages attained by the invention will become more fully apparent as the description which follows is read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a top plan view illustrating a load pusher attachment employing single folding arm assemblies constructed according to the invention;

FIG. 2 is a side elevation taken from the bottom side of the attachment in FIG. 1, with a portion of a pusher in the attachment broken away to illustrate details of construction; and

FIG. 3 is a view taken along the line 33 in FIG. 2.

Turning now to the drawings, indicated generally at 10 is a load pusher attachment of the type adapted for mounting on the telescopic mast structure of the usual industrial lift truck. The attachment includes an upright frame 12, a movable pusher 14 disposed in front of the frame, and a pair of folding arm assemblies 16, 18 as contemplated by the invention interconnecting the frame and pusher, with one arm assembly being provided for each side of the pusher.

Frame 12 is a box-type structure including sides 20, 22 suitably joined by transverse pieces, such as piece 24 (FIG. 1). With the attachment mounted on a life truck, the frame is suitably mounted on bracket structure 26 (shown in dashed outline) detachably mounted on a mounting plate 28 (also shown in dashed outline) found on the elevatable carriage in the lift truck (not shown).

Pusher 14 might be employed to push loads off of a pair of forks mounted on the lift truck carriage. Such forks, one of which is shown in dashed outline at 30, project forwardly of frame 12 under the pusher, and are mounted on bracket structure 26.

Pusher 14 comprises an upright rack of substantially rectangular outline including top and bottom parts 32, 34, respectively, and sides 36, 38 joining the top and bottom parts. The pusher, on being moved forwardly from frame 12, is adapted to push against a load such as load 40 resting on forks 30, to move the load off the forks.

Further describing the arm assemblies, and considering arm assembly 16, it comprises a primary arm 42 and a secondary arm 44. Arms 42, 44 are elongated channel members, having central webs 42a, 4411, respectively, and pairs of opposed flanges 42b, 44b, respectively, integral with the webs which are disposed at right angles to the webs. The arms are oriented with their central webs occupying substantially vertical planes. Arm 44 is somewhat narrower than arm 42, and thus so dimensioned that upon folding up of the arms, it can nest within the channel member forming arm 42.

The rear end of arm 42 is fastened, as by welding of its web and flanges to the base of an elongated upright tube, or torque shaft, 46 with the arm radiated from the tube. Tube 46, in turn, is journaled on an elongated upright pin 48 suitably mounted adjacent side 20 of frame 12. The forward end of arm 42 is hinged to the rear end of arm 44 through an elongated sleeve 50 joined as by welding to the web and flanges of arm 44 and received between the flanges of arm 42, and a pin 52 having opposite ends extending through the sleeve, and through flanges 42b of arm 42.

The forward end of arm 44 is mounted at vertically spaced points on pusher 14 adjacent side 38 of the pusher through an elongated upright mounting agency, indicated generally at 54. As can be seen clearly in FIGS. 2 and 3, mounting agency 54 comprises an elongated upright post 54a disposed with the web of secondary arm 44 paralleling the axis of the post. The post is rigidly secured to the secondary arm as by welding of the web and flanges in the arm to the side of the post.

It will be noted that whereas the post projects only a slight distance below the secondary arm, it projects an appreciably greater distance above the arm. These projecting ends of the post provide a mounting for a pair of rollera 54]) journaled on the ends which have relatively wide- 1y vertically spaced positions on the side of the pusher. Rollers 5412 are received within a pair of vertically spaced, parallel, opposing channels, or guides, 56, 58 which are secured in a suitable manner to the rear side of the pusher.

Arm assembly 18 is similar in construction to assembly 16, and includes a primary arm 60 corresponding to arm 42, and a secondary arm 62 corresponding to arm 44. Arms 60, 62 are hinged through a sleeve 64 corresponding to sleeve 50 and a pin 66 corresponding to pin 52. The rear end of arm 60 is anchored to a tube, or torque shaft, 68 that corresponds to tube 46, and tube 68 is journaled on an elongated upright pin 70 which is suitably mounted on frame 12 adjacent side 22 of the frame. The forward end of arm 62 is mounted on pusher 14 adjacent side 36 of the pusher through a mounting agency 72 including a part 72a corresponding to agency 54 and post 54a, and a pair of channels 74, 76 that corresponds to channels 56, 58.

It will be noted that secondary arm 62 directly overlies secondary arm 44 discussed in connection with the opposite side of the pusher. Post 72a has substantially the same length as post 54a, and while projecting a slight distance above secondary arm 62, projects a considerably greater distance below the arm. In this way, the rollers 72b which are mounted on the ends of the post are disposed at relatively widely vertically spaced points on the pusher. It is preferred that channels 74, 76 which receive rollers 72b be mounted at substantially the same elevation as channels 56, 58, respectively, discussed in connection with secondary arm 44, whereby post 7211 has substantially the same elevation with respect to the pusher as does the post 54a.

Arms 44, 62 are interconnected through a suitable pivot connection 78 which provides a substantially upright pivot axis for the arms. In addition, arm 62 is connected to pusher 14 through a link 80 having one end pivotally connected to the arm at 82, and the other end pivotally connected to the pusher at 84. Link 80 serves to center the pusher on arms 44, 62.

Referring to FIG. 1, the arm structures are folded up and unfolded through operation of a pair of hydraulic rams 86, 88. Ram 86 has its cylinder end pivotally mounted on frame 12 through a suitable pivot connection 90, and its rod end pivotally connected at 92 to a crank 94. Crank 94 is anchored to and radiates from tube 46. Similarly, ram 88 has its cylinder end pivotally mounted on the frame through a pivot connection 96, and its rod end pivotally connected at 98 to a crank 100 which is anchored to tube 68. Suitable hydraulic supply means (not shown) is provided for producing simultaneous actuation of the rams.

Explaining now how the apparatus described operates, on contraction of the rams, tubes 46, 68 rotate and cause the arm assemblies to fold up with the secondary arms thereof nesting within the channels of the primary arms. As the arm assemblies fold up, the forward ends of arms 44, 62 shift apart from one another toward opposite sides of the pusher, and the pusher moves inwardly toward the front of frame 12. On extension of the rams, tubes 46, 68 rotate to unfold the arm assemblies, with the forward ends of arms 44, 62 moving inwardly on the pusher and forcing it forwardly away from frame 12.

Summarizing some of the features of the invention herein disclosed, it will be noted that all points of connection between each side of the pusher and frame 12 (rollers 54b for side 38 of the pusher) are established through a single unit arm (secondary arm 44 for side 38 of the pusher) in the arm structure which supports such pusher side. This recondary arm in turn is forced to fold and unfold by reason of a hinge connection with a primary arm (arm 42 in the case of side 38 of the pusher) which is fastened to torque shaft 46 at one region of the shaft. As a consequence, upon rotation of the torque shaft, all arm structure connected to the shaft unfolds in a coordinated manner (the arm structure comprising a single arm assembly) with the rollers at the forward end of the secondary arm of the assembly always remaining in a vertically aligned position.

Even though the secondary arm of one arm assembly overlies the secondary arm of the other, a balanced pushing force is exerted on the pusher by the inclusion of the mounting agencies described featuring posts on opposites of the structure that have substantially the same elevation.

The use of channel members as contemplated for the primary and secondary arms in an arm assembly has a number of particular advantages. For one thing, it enables the two arms in an arm assembly to nest, one within another, upon contraction of the arm assembly and drawing in of the pusher toward frame 12. Further, by use of channel members and with the members disposed with their central webs in a substantially vertical plane, requisite rigidity is obtained in each arm, a strong hinge connection is provided between the two arms in an arm assembly, and a strong connection between the secondary arm and a mounting agency through a post in the agency is permitted.

With the arms in an arm assembly being nestable One within the other on contraction of the pusher, a fully compacted state may be realized in the arm assembly with the two single arm assemblies which support opposite sides of the pusher located well downwardly on the pusher from its top side. Thus, maximum visibility is afforded any operator of a lift truck which has the attachment mounted thereon.

While an embodiment of the invention has been described herein, it is appreciated that variations and modifications may be made without departing from the spirit of the invention.

I claim:

1. In a load pusher attachment including an upright frame and a pusher in front of and adapted to be forced forwardly of the frame,

a pair of upright torque shafts journaled on opposite sides of the frame, and

means consisting of a single folding arm assembly connected to each torque shaft operable to extend the pusher with rotation of the shafts,

one folding arm assembly including a primary arm joined adjacent its rear end to the base of one torque shaft, and a secondary arm hinged adjacent its rear end to said primary arm, said secondary arm having an upright mounting agency joined to its for- 5 ward end mounted at vertically spaced points on one side of said pusher and said secondary arm constituting the sole support for said one side of said pusher, the other folding arm assembly including another primary arm directly overlying the first-mentioned primary arm and joined adjacent its rear end to the other torque shaft and another secondary arm hinged adjacent its rear end to said other primary arm, said other secondary arm having an upright mounting agency joined to its forward end mounted at vertically spaced points on the other side of said pusher and said other secondary arm constituting the sole support for said other side of said pusher, the mounting agency which is joined to said first-mentioned secondary arm extending upwardly therefrom, the mounting agency joined to said second-mentioned secondary arm extending downwardly therefrom, the mounting agencies for the two secondary arms having substantially the same length and being positioned at substantially the same elevation on a pusher, said pusher having vertically spaced guide means mounted thereon receiving opposite ends of said mounting agencies and guiding the mounting agencies for movement transversely of the pusher. 2. The attachment of claim 1, wherein said primary and secondary arms are formed form channel members,

each including a central Web bounded by flanges disposed normal to the web, the webs of the channel members occupy substantially vertical planes, and the channel member forming the secondary arm in each arm assembly is nestable within the channel member forming the primary arm of the assembly.

3. The structure of claim 2, wherein, in each folding arm assembly, the primary and secondary arms are hinged through an elongated sleeve having a side joined to the web of the secondary arm and opposite ends joined to the flanges of the arm, and an elongated pin extending through said sleeve with ends of the pin received in the flanges of the primary arm.

4. The structure of claim 2, wherein said agencies joined to the forward ends of said secondary arms comprise posts anchored to the flanges and webs of the secondary arms, with rollers journaled on opposite ends of said posts.

References Cited UNITED STATES PATENTS 3,197,053 7/1965 Faust 214-514 ALBERT J. MAKAY, Primary Examiner U.S. Cl. X.R. 214-73O 

